Datacenters are able to provide their large computing and/or storage resources through the networking of large numbers of computing and/or storage resources. As the amounts of data that datacenters are called upon to process and/or store continue to increase, the corresponding increases in traffic on datacenter networks can place strains on datacenters that can negatively impact performance. Traditionally, datacenters implement Internet Protocol (IP)/Transmission Control Protocol (TCP) to handle the traffic on their networks.
Such approaches combine advantages of connectionless packet switching at lower layers, such as the datalink and/or network layers, with the advantages of connection-based switching at a higher layer, e.g., the transport layer. At lower layers, the connectionless, packet switching allows determinations to be made at individual network nodes about the path an individual packet describes through the datacenter. Multiple benefits may arise from the use of a connectionless, packet-switching protocol at one or more lower layers, such as the ability to engage in load balancing at individual network nodes, the fuller utilization of network links, fault tolerance, and/or improved bandwidth, among others.
At one or more higher layers, such as the transport layer, a suite of networking protocols in a datacenter may include a protocol, such as TCP, that may create an abstraction, such as a virtual circuit. The abstraction, or virtual circuit, between source and destination hosts in a network may provide some of the advantages of circuit switching. Such a protocol may, for example, buffer packets, reorder packets in their correct order, remove packet overhead, provide reliability measures like error detection and automatic repeat requests, and/or even provide measures to stabilize the bit rate. As a result, traffic in such datacenters can be described in terms of traffic flows between source and destination hosts. Within the foregoing environment, innovations may be made to accommodate the increasing demands of network traffic and/or improve management of network traffic in datacenters.